Attachment plug



H. A. WITCHER ATTACHMENT PLUG July 10, 1934.

Filed Oct. 21, 1952 Inventor H. A Wz'icher Patented July 10, 1934 UNITEDSTATES PATENT OFF-ICE 1 Claim.

This invention relates to an electric attachment plug, the generalobject of the invention being to provide means for locking the two partsof the plug together so that there is no danger of the two parts pullingapart, as often occurs in the plugs as now constructed, with simplemeans for unlocking the parts when desired.

This invention also consists in certain other features of constructionand in the combination and arrangement of the several parts to behereinafter fully described, illustrated in the accompanying drawing andspecifically pointed out in the appended claim.

In describing the invention in detail, reference will be had to theaccompanying drawing wherein like characters denote like orcorresponding parts throughout the several views, and in which:-

Figure 1 is an elevation of the plug.

Fig. 2 is a section on line 2--2 of Fig. 1.

Fig. 3 is a section on line 33 of Fig. 2.

Fig. 4 is a section on line 4-4. of Fig. 1.

As shown in these views, the plug A is composed of the two sections 1and 2 which are held together by the bolt 3 and the corrugated metalsleeve 4 which is threaded on the reduced part of the two sections, thispart, of course, being adapted to fit in the usual socket.

The inner face of each section is formed with a pair of elongatedrecesses 5 which are spaced apart and extend through that end of theplug which is opposite the reduced part thereof and a pair oflatch-shaped member 6 are placed in the chambers formed by the recessesof the two sections, one member being placed in each chamber and eachmember 6 is hingedly supported at one end by a pin '7 passing throughsaid end of the member 6 and having its ends entering the walls of therecess adjacent the closed end thereof. One of these members isconnected by a conductor 8 to the center contact 9 at the end of thereduced part of the plug and the other member 6 is connected by theconductor 10 with the sleeve or shell 4.

A spring 11 is arranged in each chamber and presses upon the free end ofeach member 6 and tends to move it in a direction opposite the spring.The second part or cap of the plug is shown at 12 and carries the twomembers 13 passing through the cap, one of these members 13 entering oneof the chambers and the other member the other chamber when the cap isplaced on the plug, and each member 13 is formed with a double hook l4at its inner end, either part of which is adapted to be engaged by thehook on a member 6, as shown in Fig. 3. By making the hook 14 of doubleshape, the cap is reversible and it does not matter which chamber eithermember 13 enters.

The section 2 is formed with a recess 15 which passes through a side ofthe section and a substantially Y-shaped member 16 is slidably arrangedin said recess with its stem projecting from the side of the section andwith the ends of its limbs adapted to engage the members 6 when themember 16 is pushed inwardly.

Thus it will be seen that when the cap 12 is pushed up to the end of theplug, the members 13 will have their rounded ends engage the beveledparts of the members 6 so as to move these members against the action ofthe springs 11, so that the members 13 can pass the members 6 and thenthe springs 11 will push the members 6 to a position where the hooks onsaid members 6 will engage parts of the hooks 14, and thus the cap willbe locked to the plug and the electrical connection between the parts ofthe plug and the members 13 oi the cap will be completed.

Then when it is desired to release the cap from the plug, the member 16is pressed inwardly so that its limbs will engage the members 6 andforce them away from the members 13 so that said members 13 are free tomove out of the chambers or recesses 5. Of course the wires connectedwith the cap 12 are connected to the members 13 as shown in Fig. 3.

Thus it will be seen that with this invention there is no danger of theparts of the plug being separated as they are firmly locked in positionand cannot be separated until the member 16 is pushed inwardly to movethe members 6 to releasing position.

When the device is used in a floor or wall plug suitable means may beprovided for actuating the member 16 from a point at the exposed part ofthe plug such as by a push rod connected to a cam which engages themember 16 to actuate the same.

It is thought from the foregoing description that the advantages andnovel features of the invention will be readily apparent.

It is to be understood that changes may be made in the construction andin the combination and arrangement of the several parts provided thatsuch changes fall within the scope of the appended claim.

Having thus described my invention, what I claim as new is:-

A plug of the class described comprising a body having a pair ofchambers therein opening out verse slide of substantially Y-shapelocated in one side of the plug and having its stem projecting from anexterior part thereof with the ends of its limbs adapted to engage thelatch members when the slide is pushed inwardly, to free said latchmembers from the contact members.

HORACE A. WITCHER.

